1. Field of the Invention
The present invention relates to a fire protection installation of the type comprising a normally dry network of sprinklers suitable, whenever the dry network of sprinklers is put to atmospheric pressure due to said network of sprinklers being opened, for being fed with water via a control station that is connected to a supply of water under pressure.
2. Summary of Prior Art
The purpose of a sprinkler installation is to detect the seat of a fire, to raise the alarm, and to extinguish it as it begins, or at least contain it in such a manner as to ensure that it can be properly extinguished by means available in the establishment fitted with said installation or by the fire brigade.
In premises where there is no risk of freezing, the sprinkler network may be "wet", i.e. it may be permanently filled with water.
However, when there is a risk of freezing, the sprinkler network must be "dry", i.e. empty of water, since the freezing of a wet installation can damage that installation and thus give rise to a risk of water damage, and above all, to a risk of the installation being out of operation for a greater or lesser length of time as required for bringing it back into operation.
In dry installations, the sprinkler network is maintained under air that is permanently compressed. A drop in pressure in the pressurized air sprinkler network due to a sprinkler opening because it has detected a fire causes a valve in a control station to open, thereby triggering the alarm and putting the sprinkler network into communication with the supply of water under pressure.
The drawback of present dry installations is that the air contained in the network is at a pressure of at least 2 bars. This gives rise to a relatively lengthy period of time to exhaust air from the network after it has opened, and in certain installations that can be quite unacceptable, and it also requires the installation to be provided with a compressor device enabling such pressures to be obtained. The high pressure also gives rise to condensation inside the sprinkler network, thereby leading back to the risk of ice forming therein due to freezing.